These cooling devices, as disclosed in U.S. Pat. No. 4,295,964 and in CH 533 246 A, can be used for a host of applications and are available in the most varied embodiments. The cooling device systems which have been readily available on the market to date, however, all predominantly have a filter unit flanged to the cooling unit, or have tank units connected to the cooling units with the tank unit then holding the filter element. The known cooling devices are therefore generally composed of several components. The independent cooling unit can be connected by corresponding piping to the independent filter unit as the cooling device is being produced. As a result of the piping, in the transport of the fluid, flow-induced losses occur. These losses do not favor energy-efficient operation of the known cooling device. Nor can it be precluded that leaks may occur in the area of the piping. This leaking adversely affects operating reliability.
DE 196 35 777 A discloses a cooling device with a cooling unit through which a fluid to be cooled can flow and with a filter unit for filtration of the fluid. The cooling unit and the filter unit are integrally connected to one another. The filter unit together with the cooling unit are located in a device housing. This document also discloses using a plate-shaped finned radiator as the cooling unit. The filter element is held in a filter housing in this known solution such that it is an integral component of the device housing.
U.S. Pat. No. 5,159,821 discloses a cooling device with a filter disk with a small structure in the axial direction as the filter element. The filter element is located in the device housing, and holds a plate-shaped finned radiator as the cooling unit. A drying medium extends in the fluid direction in front of the filter element within the device housing. The filter element disk connected upstream of the finned radiator on one of its longitudinal sides occupies only a small overall length there. In these known solutions as well, flow losses occur in the operation of the filter device leading to low filter efficiency. To some extent, a used filter element can be replaced by a new element only with great difficultly.
EP 1 261 809 B1 discloses a generic cooling device with a cooling unit through which a fluid to be cooled, especially hydraulic oil, can flow, and with a filter unit for filtration of the fluid. The cooling unit and the filter unit are integrally connected to one another and are located in a device housing. The cooling unit is a plate-shaped finned radiator assuming the incipient cooling tasks. The filter unit is located in the flow direction of the fluid to be cooled upstream from the plate-shaped finned radiator. This arrangement has the advantage that potential fouling, when filtered out of the fluid flow, cannot adversely affect reliable operation of the cooling unit. In the known solution the filter unit extends essentially along one longitudinal side of the finned radiator. Between the filter unit and the cooling unit, a fluid collecting chamber is connected. This fluid collecting chamber has different cross sectional areas, in particular, the cross section widens in the direction of the bottom side of the cooling device so that unfavorable flow conditions can occur with cavity formation. This collecting chamber configuration is disadvantageous for undisrupted, energy-saving operation of the known cooling device. At very low flow velocities of the fluid, the distribution of the fluid out of the fluid collecting chamber to the cooling unit leads to nonuniform distribution situations. This distribution adversely affects effective cooling of the fluid. In addition, the known solution is expensive and complex to produce.